[css-grid-1] Clarify that automatic minimum size is clamped by the max track sizing functions, not by the mins. w3c#3581

Author: fantasai

css-grid-1/Overview.bs

@@ -1246,14 +1246,17 @@ Automatic Minimum Size of Grid Items</h3>
 	otherwise its <a>transferred size suggestion</a> if that exists,
 	else its <a>content size suggestion</a>,
 	see below.
-	However, if the <a>grid item</a> spans only <a>grid tracks</a>
+	However,
+	to prevent the <a>content-based minimum size</a>
+	from forcing overflow of its fixed-size grid area,
+	if the <a>grid item</a> spans only <a>grid tracks</a>
 	that have a <a lt="fixed sizing function">fixed</a> <a>max track sizing function</a>,
 	its <a>specified size suggestion</a> and <a>content size suggestion</a> in that dimension
 	(and the input to the <a>transferred size suggestion</a> in the other dimension)
 	are further clamped to less than or equal to the <a>stretch fit</a>
-	the <a>grid area</a>’s size
-	(so as to prevent the <a>content-based minimum size</a>
-	from forcing overflow of its fixed-size grid area).
+	into the <a>grid area</a>’s maximum size,
+	as represented by the sum of those <a>grid tracks</a>’ <a>max track sizing functions</a>
+	plus any intervening <a lt="fixed sizing function">fixed</a> <a>gutters</a>.
 
 	The <a>content size suggestion</a>, <a>specified size suggestion</a>, and <a>transferred size suggestion</a>
 	used in this calculation account for the relevant min/max/preferred size properties